<?php
// This is the path to markdown.php
if ( !defined('WORDPRESS_README_MARKDOWN') ) {
    if ( defined('AUTOMATTIC_README_MARKDOWN') )
        define( 'WORDPRESS_README_MARKDOWN', AUTOMATTIC_README_MARKDOWN );
    else
        define('WORDPRESS_README_MARKDOWN', dirname(__FILE__) . '/class-markdown-parse.php');
}

Class WordPress_Readme_Parser {

    function __construct() {
        // This space intentially blank
    }

    function parse_readme( $file ) {
        $file_contents = @implode('', @file($file));
        return $this->parse_readme_contents( $file_contents );
    }

    function parse_readme_contents( $file_contents ) {
        $file_contents = str_replace(array("\r\n", "\r"), "\n", $file_contents);
        $file_contents = trim($file_contents);
        if ( 0 === strpos( $file_contents, "\xEF\xBB\xBF" ) )
            $file_contents = substr( $file_contents, 3 );

        // Markdown transformations
        $file_contents = preg_replace( "|^###([^#]+)#*?\s*?\n|im", '=$1='."\n",     $file_contents );
        $file_contents = preg_replace( "|^##([^#]+)#*?\s*?\n|im",  '==$1=='."\n",   $file_contents );
        $file_contents = preg_replace( "|^#([^#]+)#*?\s*?\n|im",   '===$1==='."\n", $file_contents );

        // === Plugin Name ===
        // Must be the very first thing.
        if ( !preg_match('|^===(.*)===|', $file_contents, $_name) )
            return array('error'); // require a name
        $name = trim($_name[1], '=');
        $name = $this->sanitize_text( $name );

        $file_contents = $this->chop_string( $file_contents, $_name[0] );


        // Requires at least: 1.5
        if ( preg_match('|Requires at least:(.*)|i', $file_contents, $_requires_at_least) )
            $requires_at_least = $this->sanitize_text($_requires_at_least[1]);
        else
            $requires_at_least = NULL;


        // Tested up to: 2.1
        if ( preg_match('|Tested up to:(.*)|i', $file_contents, $_tested_up_to) )
            $tested_up_to = $this->sanitize_text( $_tested_up_to[1] );
        else
            $tested_up_to = NULL;


        // Stable tag: 10.4-ride-the-fire-eagle-danger-day
        if ( preg_match('|Stable tag:(.*)|i', $file_contents, $_stable_tag) )
            $stable_tag = $this->sanitize_text( $_stable_tag[1] );
        else
            $stable_tag = NULL; // we assume trunk, but don't set it here to tell the difference between specified trunk and default trunk


        // Tags: some tag, another tag, we like tags
        if ( preg_match('|Tags:(.*)|i', $file_contents, $_tags) ) {
            $tags = preg_split('|,[\s]*?|', trim($_tags[1]));
            foreach ( array_keys($tags) as $t )
                $tags[$t] = $this->sanitize_text( $tags[$t] );
        } else {
            $tags = array();
        }


        // Contributors: markjaquith, mdawaffe, zefrank
        $contributors = array();
        if ( preg_match('|Contributors:(.*)|i', $file_contents, $_contributors) ) {
            $temp_contributors = preg_split('|,[\s]*|', trim($_contributors[1]));
            foreach ( array_keys($temp_contributors) as $c ) {
                $tmp_sanitized = $this->user_sanitize( $temp_contributors[$c] );
                if ( strlen(trim($tmp_sanitized)) > 0 )
                    $contributors[$c] = $tmp_sanitized;
                unset($tmp_sanitized);
            }
        }


        // Donate Link: URL
        if ( preg_match('|Donate link:(.*)|i', $file_contents, $_donate_link) )
            $donate_link = esc_url( $_donate_link[1] );
        else
            $donate_link = NULL;


        // togs, conts, etc are optional and order shouldn't matter.  So we chop them only after we've grabbed their values.
        foreach ( array('tags', 'contributors', 'requires_at_least', 'tested_up_to', 'stable_tag', 'donate_link') as $chop ) {
            if ( $$chop ) {
                $_chop = '_' . $chop;
                $file_contents = $this->chop_string( $file_contents, ${$_chop}[0] );
            }
        }

        $file_contents = trim($file_contents);


        // short-description fu
        if ( !preg_match('/(^(.*?))^[\s]*=+?[\s]*.+?[\s]*=+?/ms', $file_contents, $_short_description) )
            $_short_description = array( 1 => &$file_contents, 2 => &$file_contents );
        $short_desc_filtered = $this->sanitize_text( $_short_description[2] );
        $short_desc_length = strlen($short_desc_filtered);
        $short_description = substr($short_desc_filtered, 0, 150);
        if ( $short_desc_length > strlen($short_description) )
            $truncated = true;
        else
            $truncated = false;
        if ( $_short_description[1] )
            $file_contents = $this->chop_string( $file_contents, $_short_description[1] ); // yes, the [1] is intentional

        // == Section ==
        // Break into sections
        // $_sections[0] will be the title of the first section, $_sections[1] will be the content of the first section
        // the array alternates from there:  title2, content2, title3, content3... and so forth
        $_sections = preg_split('/^[\s]*==[\s]*(.+?)[\s]*==/m', $file_contents, -1, PREG_SPLIT_DELIM_CAPTURE|PREG_SPLIT_NO_EMPTY);

        $sections = array();
        for ( $i=1; $i <= count($_sections); $i +=2 ) {
            $_sections[$i] = preg_replace('/^[\s]*=[\s]+(.+?)[\s]+=/m', '<h4>$1</h4>', $_sections[$i]);
            $_sections[$i] = $this->filter_text( $_sections[$i], true );
            $title = $this->sanitize_text( $_sections[$i-1] );
            $sections[str_replace(' ', '_', strtolower($title))] = array('title' => $title, 'content' => $_sections[$i]);
        }


        // Special sections
        // This is where we nab our special sections, so we can enforce their order and treat them differently, if needed
        // upgrade_notice is not a section, but parse it like it is for now
        $final_sections = array();
        foreach ( array('description', 'installation', 'frequently_asked_questions', 'screenshots', 'changelog', 'change_log', 'upgrade_notice') as $special_section ) {
            if ( isset($sections[$special_section]) ) {
                $final_sections[$special_section] = $sections[$special_section]['content'];
                unset($sections[$special_section]);
            }
        }
        if ( isset($final_sections['change_log']) && empty($final_sections['changelog']) )
            $final_sections['changelog'] = $final_sections['change_log'];


        $final_screenshots = array();
        if ( isset($final_sections['screenshots']) ) {
            preg_match_all('|<li>(.*?)</li>|s', $final_sections['screenshots'], $screenshots, PREG_SET_ORDER);
            if ( $screenshots ) {
                foreach ( (array) $screenshots as $ss )
                    $final_screenshots[] = $ss[1];
            }
        }

        // Parse the upgrade_notice section specially:
        // 1.0 => blah, 1.1 => fnord
        if ( isset($final_sections['upgrade_notice']) ) {
            $upgrade_notice = array();
            $split = preg_split( '#<h4>(.*?)</h4>#', $final_sections['upgrade_notice'], -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
            for ( $i = 0; $i < count( $split ); $i += 2 )
                $upgrade_notice[$this->sanitize_text( $split[$i] )] = substr( $this->sanitize_text( $split[$i + 1] ), 0, 300 );
            unset( $final_sections['upgrade_notice'] );
        }

        // No description?
        // No problem... we'll just fall back to the old style of description
        // We'll even let you use markup this time!
        $excerpt = false;
        if ( !isset($final_sections['description']) ) {
            $final_sections = array_merge(array('description' => $this->filter_text( $_short_description[2], true )), $final_sections);
            $excerpt = true;
        }


        // dump the non-special sections into $remaining_content
        // their order will be determined by their original order in the readme.txt
        $remaining_content = '';
        foreach ( $sections as $s_name => $s_data ) {
            $remaining_content .= "\n<h3>{$s_data['title']}</h3>\n{$s_data['content']}";
        }
        $remaining_content = trim($remaining_content);


        // All done!
        // $r['tags'] and $r['contributors'] are simple arrays
        // $r['sections'] is an array with named elements
        $r = array(
            'name' => $name,
            'tags' => $tags,
            'requires_at_least' => $requires_at_least,
            'tested_up_to' => $tested_up_to,
            'stable_tag' => $stable_tag,
            'contributors' => $contributors,
            'donate_link' => $donate_link,
            'short_description' => $short_description,
            'screenshots' => $final_screenshots,
            'is_excerpt' => $excerpt,
            'is_truncated' => $truncated,
            'sections' => $final_sections,
            'remaining_content' => $remaining_content,
            'upgrade_notice' => $upgrade_notice
        );

        return $r;
    }

    function chop_string( $string, $chop ) { // chop a "prefix" from a string: Agressive! uses strstr not 0 === strpos
        if ( $_string = strstr($string, $chop) ) {
            $_string = substr($_string, strlen($chop));
            return trim($_string);
        } else {
            return trim($string);
        }
    }

    function user_sanitize( $text, $strict = false ) { // whitelisted chars
        if ( function_exists('user_sanitize') ) // bbPress native
            return user_sanitize( $text, $strict );

        if ( $strict ) {
            $text = preg_replace('/[^a-z0-9-]/i', '', $text);
            $text = preg_replace('|-+|', '-', $text);
        } else {
            $text = preg_replace('/[^a-z0-9_-]/i', '', $text);
        }
        return $text;
    }

    function sanitize_text( $text ) { // not fancy
        $text = strip_tags($text);
        $text = esc_html($text);
        $text = trim($text);
        return $text;
    }

    function filter_text( $text, $markdown = false ) { // fancy, Markdown
        $text = trim($text);

        $text = call_user_func( array( __CLASS__, 'code_trick' ), $text, $markdown ); // A better parser than Markdown's for: backticks -> CODE

        if ( $markdown ) { // Parse markdown.
            if ( !function_exists('Markdown') )
                require( WORDPRESS_README_MARKDOWN );
            $text = Markdown($text);
        }

        $allowed = array(
            'a' => array(
                'href' => array(),
                'title' => array(),
                'rel' => array()),
            'blockquote' => array('cite' => array()),
            'br' => array(),
            'p' => array(),
            'code' => array(),
            'pre' => array(),
            'em' => array(),
            'strong' => array(),
            'ul' => array(),
            'ol' => array(),
            'li' => array(),
            'h3' => array(),
            'h4' => array()
        );

        $text = balanceTags($text);

        $text = wp_kses( $text, $allowed );
        $text = trim($text);
        return $text;
    }

    function code_trick( $text, $markdown ) { // Don't use bbPress native function - it's incompatible with Markdown
        // If doing markdown, first take any user formatted code blocks and turn them into backticks so that
        // markdown will preserve things like underscores in code blocks
        if ( $markdown )
            $text = preg_replace_callback("!(<pre><code>|<code>)(.*?)(</code></pre>|</code>)!s", array( __CLASS__,'decodeit'), $text);

        $text = str_replace(array("\r\n", "\r"), "\n", $text);
        if ( !$markdown ) {
            // This gets the "inline" code blocks, but can't be used with Markdown.
            $text = preg_replace_callback("|(`)(.*?)`|", array( __CLASS__, 'encodeit'), $text);
            // This gets the "block level" code blocks and converts them to PRE CODE
            $text = preg_replace_callback("!(^|\n)`(.*?)`!s", array( __CLASS__, 'encodeit'), $text);
        } else {
            // Markdown can do inline code, we convert bbPress style block level code to Markdown style
            $text = preg_replace_callback("!(^|\n)([ \t]*?)`(.*?)`!s", array( __CLASS__, 'indent'), $text);
        }
        return $text;
    }

    function indent( $matches ) {
        $text = $matches[3];
        $text = preg_replace('|^|m', $matches[2] . '    ', $text);
        return $matches[1] . $text;
    }

    function encodeit( $matches ) {
        if ( function_exists('encodeit') ) // bbPress native
            return encodeit( $matches );

        $text = trim($matches[2]);
        $text = htmlspecialchars($text, ENT_QUOTES);
        $text = str_replace(array("\r\n", "\r"), "\n", $text);
        $text = preg_replace("|\n\n\n+|", "\n\n", $text);
        $text = str_replace('&amp;lt;', '&lt;', $text);
        $text = str_replace('&amp;gt;', '&gt;', $text);
        $text = "<code>$text</code>";
        if ( "`" != $matches[1] )
            $text = "<pre>$text</pre>";
        return $text;
    }

    function decodeit( $matches ) {
        if ( function_exists('decodeit') ) // bbPress native
            return decodeit( $matches );

        $text = $matches[2];
        $trans_table = array_flip(get_html_translation_table(HTML_ENTITIES));
        $text = strtr($text, $trans_table);
        $text = str_replace('<br />', '', $text);
        $text = str_replace('&#38;', '&', $text);
        $text = str_replace('&#39;', "'", $text);
        if ( '<pre><code>' == $matches[1] )
            $text = "\n$text\n";
        return "`$text`";
    }

} // end class
